Make your own free website on Tripod.com

Microcrystalline Cellulose

Microcrystalline cellulose has very limited use. That is, however, unless you're pressing pills/tablets. It is the most universal and quite possibly the best base excipient for making pills. It acts as a disintegrant, a tough binder, and a lubricant to a slight degree. Unfortunately it is also quite expensive to purchase, and even harder to find a legitimate supplier that will sell to residences. However, the process to make it at home is astonishingly simple. The reason for the high cost is due to the elaborate manufacturing process employed on an industrial level which becomes quite expensive since this material is bulky. Not to mention, previous processes for producing this were quite inefficient and/or required expensive starting materials.

Reaction:

There is no real reaction scheme, so I can't write up an equation. At first, a cellulose pulp is hydrolyzed with sodium hydroxide. This dissolves most of the pentosan, and hemicellulose and also converts some of the cellulose. It is washed free of this, then is hydrolyzed with hydrochloric acid to break down the amorphous and somewhat chaotic organization of cellulose, into a more crystalline form of cellulose - hence the name microcrystalline cellulose.

Materials
Equipment
Ordinary white paper Blender/Food processor
Sodium hydroxide Large (2000ml+) beaker or cheap saucepan
31.45% Hydrochloric acid Large strainer
  Pieces of T-shirt to fit in large strainer
  5 gallon plastic bucket

First, obtain roughly 100g of ordinary paper. Fresh computer paper is recommended, but you can use recycled paper. However, newspaper (or anything similar) is not recommended. If using ordinary computer paper, it will take between 20-25 sheets to obtain roughly 100g. Cut the sheets into 16ths and place in a blender with a little hot water. Blend it up until its quite smooth. This is your paper pulp. Depending on the dyes or bleaching agents used in the paper, it could be blue or purple - this will go away. Add roughly 1000ml of hot water to your 2000ml beaker, or teflon coated saucepan. Add to this, 50g of sodium hydroxide. Thoroughly dissolve the sodium hydroxide, then add the paper pulp from the blender. Heat this up and hold it at an average of 60C for 60minutes minimum. Stir it occasionally.

Once it's done cooking, flood it with water. Set up your strainer with the T-shirt pieces to make a coarse filter. Set the strainer up above the 5 gallon bucket. Pour the contents through this. The filtrate should be a milky color - similar to starch in water. The material in the filter is what you want. Put latex gloves on, and ring out the material in the filter. Get as much water out as possible. In a very large stock pot, add around 1 gallon of hot water. Add the filtered paper pulp to this, and stir it well. Filter this out. Repeat this two more times, and on the third time all the soluble products and remaining sodium hydroxide should be gone. The wash water in the bucket can simply be dumped down the drain.

Ring the pulp out well one last time, and add it again to the 2000ml beaker, or teflon coated saucepan. Add another 1000ml of hot water, then add 150-160ml of 31.45% hydrochloric acid (muriatic acid). Bring this up to an average of 90C and hold it there for at least 2 hours. Add more water if it boils away. Once done, again flood it with water, and set up your strainer over the 5 gallon bucket.

Pour the pulp through the filter/strainer. You will notice the pulp now has a subtle difference in it's properties. While waiting for it to drain, fill up the stock pot with 1 gallon of hot water. Do not ring the water out of the pulp this time. If you do, it will clump very tight and make it quite hard to wash it. Add it directly to the hot water and stir it well. Repeat that step two more times, making sure not to ring it out in between each wash. This product should now be completely free of acid and any soluble chemicals. After the final straining, ring it out very well. Get as much water out as possible, as it will quicken the drying process. The water in the bucket can simply be poured down the drain. When you unravel the t-shirt, you will notice it is now tightly clumped and very hard. These are the exact properties that make microcrystalline cellulose important. Place it in your blender to chew it up into finer particles - close to the consistency of crumbs. Spread this on a foil lined cookie sheet in a very thin layer. Throw it in the oven at 300F (150C) for 1-2 hours. When removed, it should be crunchy sounding, as opposed to the very soft feel of paper that we started with. Last time I did this, I obtained 56g of dried product.

Special note: Final product should be colorless and odorless. If it is to be used in consumable pills/tablets, it must be completely white - no tints of the rainbow. Also, if it is pharmaceutical grade, you must use all glass cooking materials. The first time I performed this experiment, I used a teflon coated aluminum saucepan. The teflon coating was eaten away in some places, so the aluminum dissolved to a small extent and I was left with a slightly gray product. This is of course from aluminum hydroxide, which isn't specifically poisonous, but it's not always the visible things that can harm you...